Pump



F. w.- oFELDT PUMP \ Oct. 4, 1938.

Filed June 29, 195e 4 sheets-sheet 1 Oct. 4, 1938. 1 F. w. OFI-:LDT

PUMP

Filed June 29, "i956 4 sheets-sheet s y I A* INVENTOR.

` ATTORNEY.

F. W. OFELDT Oct. 4, 1938.

PUMP

Filed June 29, 1936 4 Sheets-Sheet 4 the intake valve during the pressure Patented Oct. 4, 1938 Frank W.y Ofeldt, McKeesport, Pa., assgnor to Homestead Valve Manufacturing Company, Coraopolis,l Pa., a corporation of Pennsylvania Application June 29, 193s, serial No. 87,847

12 Claims.

operation. Again the pump may be conveniently employed for pumping fluids .carrying insoluble substances in suspension which would prevent the proper seating of the valves of an ordinary displacement pump.

' Displacement pumps generally employ poppet or ball check type intake .valves which usuallyy depend upon the suction pressure developed by the piston for their operation. The timing of suc'A l tion operated valvesisnot dependable and materially reduces the capacity and the eiiciency of the pump. Again the suction force developed by the pump is not sufficient to overcome the sticking action whenpumping viscous or sticky vfluids which cause the valves to adhere to their seats with a greater force than that developed by the suction of the pump.

I overcome these disadvantages' by the provision of mechanical means for positively actuating the intake valve to lift it from its seat. This v positive movement of the valve overcomes any adhesion forces created by the viscous or sticky fluid being pumped. l

Again I provide means for positively actuating' the intake valve to seat the same and do not rely upon the fluid pressure developed by the pump to close the valve.

The provision of these positive actions for operating the valves of a displacement pump increases the overall hydraulic efficiency of the pump, as the suction and fluid pressure developed by the pump are expended to act only on the fluid being pumped.

Again I am enabled to accurately time the loss in eiiiciency by forcing fluid back through period of the pumping cycle.

Another object of my invention is the provision of means for seating and unseating the valves of a displacement pump during the period of the highest speed of the. movement of the valves. The operation of the valves in this manner Vis conducive to accurate timing which'aids in increasing the pumping reiiiciency.v Again -I am enabled to produce or to prevent back flow a reciprocating member and preventing leakage showing a modication thereof.

through ythe intake valves, which permits the use of a part or all of the full stroke of the pumppiston tovary the displacement and hence the output. 'Ihese results are not known to be attainable by cam operated valves of any previous displacement pump. The speed of the movement of the valve when seating, dislodges any insoluble substance from its seat which prolongs the usefulness of the valve without necessity of cleaning or refinishing -the valve seating surfaces.

Another object of this invention Ais the provision of means for varying the capacity of a. reciprocating displacement pump that is operated at constant speed.

Another object is'the provision of a method for adjusting the seating of the valves in a displacement pump. n

Another object is the provision of means for preventing foreign iiuids and the uid being lpumped from being transmitted along the reciprocating piston to commingle with one an# other. v l

Another object is the provision of lubricating of the lubricant therefrom.

Another object is the provision of means for .controlling the pressure ofthe delivery of the fluid being pumped.

Other objects and advantages appear hereinafter.

In the accompanying drawings wherein I have illustrated a practical embodiment of the principles of my invention:

Figure 1 is a vertical section of the pump comprising my invention taken along the line I-I of Fig. 2. a

Fig. 2 is a horizontal section showing a triplex pump comprising my invention. Y

Fig. 3 is an end elevation of the pump showing the head blek. f

Fig. 4 is a. sectional view taken along the line 4-4 of Fig. 1. operation of the valves and thereby avoid any Fig. 5 is a plan view of the pump head block Fig. 6 is a side elevation of the pump head block shown in Fig. 5.

Fig. 'l is a sectional view taken along the-line i-'l of Fig. 5.

Referring to Figs. 1 to 4 of the drawings, I0 50 represents the pump casing enclosed at one end thereof by the cover Il. The sides of the casing are provided with the bearing assemblies l2 far--- ranged to carry the drive shaft I3 which extends through walls of the casing. I4 represents oil 55 throwerswhich prevent the escape of oil past the cap plates. The outer ends of the drive shaft are arranged to be coupled with a suitable source of vrotary power or other rotary device for driving the pump from either side, or for driving another device through said shaft.

I5 represents bosses on the exterior of the sides of the casing I0. Aligned holes are drilled in these bosses to receive the stationary crank shaft I6 which is pressed thereinto. I1 represents a crank shaft sleeve rotatably supported on. the shaft I6 and having formed thereon the eccentric cranks I8, I9 and-20. The sleeve I1 is hoilowed out within the eccentrics to form the lubricant reservoirs 2I. These reservoirs are fed by the passageways 22 extending Ato the exterior of the sleeve where they receive oil from the crank case by the splash system. The level of the oil within the crank case is indicated in Fig. 1.

23 represents thrust 'washers 'mounted on the opposite ends of the shaft I6 between the sides of the crank case and the ends of the crank shaft sleeve I1. It will be noted that clearance is provided between the sleeve I1 and the thrust wash ers 23, as indicatedat the right in Fig. 2, to permit limited end play of the sleeve.

The end of the sleeve I1 adjacent the eccentric crank 26 is finished to receive the helical gear 24 which is secured to the sleeve, as by means of the bolt 25 that passes through the gear and the eccentric 20 and is held in place by the lock washer and nut 26. The gear 24 is arranged to mesh with the helical pinion 21 formed on the drive shaft I3. The bottom of the casing is enlarged to receive the gear 24.

28 represents a plug on the top of the casing which may be removed for the introduction of oil. 29 represents the oil drain plug at the bot torn of the casing.

3II, 3I and 32 represent connecting rods, the crank shaft bearings of which form straps arranged to encompass the eccentrics I8, I9 and 2B. The other ends of these connecting rods are pivotally secured to the crossheads 33, 34 and 35 by means of the wrist pins 36. Each of these cross heads are arranged to be reciprocated within their respective bores in the body of the pump casing.

- The crossheads 33, 34 and 35 comprise a hollowed-body portion 31 and concentric cylindrical extensions 38 of smaller diameter which extend through the bores in the body of the casing. These extensions are sealed within their respective bores by any suitable packing members 39 such as the cup washer type of oil seal. the end Aof the body portion o f each crosshead forms a pump piston for drawing and expelling oil through the passageways 31a in the head of the body portions 31 to lubricate the crossheads as they reciprocate within their respective bores in the body of the pump casing.

The sides of the outer end of the casing body I0 are provided with the outwardly extending spacer abutments 40 upon which is mounted the pump casing head 4I. cured to the pump body I8 by means of the stud bolts 42 held by the nuts 43. y

44, 45 and 46 represent the pumping chambers in the head v4I arranged to receive the pump pistons 41, 48, 49 respectively. The pump pistons A are preferably of the same diameter and form an integral part of the crosshead extensions 38 but are separated therefrom by the cylindrical portions or necks 50 of reduced diameter.

As indicated in Fig. 1, the pump is arranged Thus 'I'he casing head is sealong the piston to the packing 39 and the crank case, I provide the pistons with the reduced sections 50. Any liquid traveling along the surface thereof would have to climb the radial shoulders 5I,'which form the reduced portion 50, in order to completely traverse the piston. The liquids will collect at the bottom of the radial shoulders 5I of the horizontal pistons and be thrown therefrom by inertia as the pistons are reciprocated. The liquids will thus drop from the pump casing to the floor without harming their opposite packings or polluting each other which may lead to destruction. y

52 represents the packing chambers for the pumping pistons 41, 48 and 49. These chambers are provided with the packing elements 53 held in place by the 'gland members 54.

The outer end of the pump head 4I is provided with the plugs 55 and 56 which are oppositely disposed to the pumping pistons and the intake valves 51 respectively.

y These intake valves are of the poppet type, having the head 58 and the stem 59 guided by the member 6D. The head is arranged to seat on the valve seat member 6I.

62 represents an adjusting nut secured on the threaded end of the stem 59 by means of the lock nut 63. The nut 63 is arranged to support one end of the helical valve spring 64 which is held at its other end by the cap member 65. The cap member-65 carries the packing 66 for sealing the valve stem 59 against outward leakage. Thus the spring 64 seats the valve and holds the packing 66 against the valve guide member 6I! to automatically compensate for the wear of the packing.

The intake valves are operated by the tappets 61 which engage the adjusting nut 62 when reciprocated by the tappet lever or bell crank members 68 pivotally supported on the rod 69.

The rod 69 is held in the lugs 10 integral with the casing body I0 within the crank case. 'I'he ends of the tappets 61 are shaped to freely ride on the arcuate surface 1I of the lever or bell crank member 68 when the latter are oscillated.

The lever or bell crank members 68 are provided with the tail portions 12 arranged to en- .gage and ride on the perimetral surface of the The operating cycle of the lever or bell crank 68 is therefore ninety degrees out of phase with that of the pump piston. As shown in Fig. 1 of the drawings, the valve adjusting nut 62 is arranged so that the valve will commence to open as the piston 49 commences its suction stroke and the strap of the connecting rod 32 moves the lever or bell cranky tail 12 upwardly, assuming the pump to be disposed in a horizontal position. The valve 51 will be fully opened when the piston is half way down its stroke and the eccentric crank armlha's moved through ninety degrees. From this point the valve 51 will begin to close and will be fully closed when the eccen- .tric crank reaches the position of one hundred and eighty'degrees from that shown. During the pressure stroke of the pumping cycle the valve 51V remains seated and the lever or bell crank tail 12 may ride free on the strap 32.

When the valve 51 is fully opened the eccentric crank is vertical. Graphically this point may be indicated as the crest of a sine curve representing the valve .operating cycle. The movement of the valve is therefore slowest at this point. The fastest movement of the valve occurs at *the instants that it is opened and closed, which' may be represented graphically by the points of intersection of the sine curve with the base or zero line. The graphic representation of the inlet valve operating cycle with respect to time would then Abea series of the positive halves .of a sine curve, as the valve is not ordinarily. operated during the other half, of the cycle. Under these conditions the pump will operatejat maximum capacity. f

By positioning the valve adjusting nut 62 further up the stem than that shown in Fig. 1,

the opening of the valve will be delayed and its closing will be hastened, thus reducing the time that the inlet valve 51 is open and consequently reducing the output capacity of the pump.

With this setting of the-valve 51 the discharge of the pump starts, in point ofA time, after the beginning of the pump-pressure stroke and continues to the end of the pump pressure stroke. The vacuum created during the first part of the pump suction stroke is suiicient to permit the flow of a volume of fluid, into the pump chamber, equal to that displaced by the pump piston when the inlet valve opens. This destroys the vacuum formed duringv the first part of the suction stroke. The piston will continue to draw in fluid until'the inlet valve closes. The piston then completes its suction stroke without drawing any more of the fluid'into the pump chamber, which creates a vacuum during the last part of ther suction stroke. During the pressure stroke the pump piston must move initially through the same4 displacement to destroy the vacuum and before l any pressure will. be developed in the chamber to cause a discharge of uid from the chamber. The displacement by-the piston then continues until the end of the pressure stroke. By setting the inlet valve 51 in this manner the pump capacity may be reduced to only one-half of its full displacement. This limitation is of course based ,upon the assumption that the operating speed of the pump and viscosity of the fluid are not contributing factors.

Likewise by screwing out -theadjusting nut 62' 4from the position shown in Fig. 1 the.`closing of .the valve 51 will be delayed to a time laggingthe beginning of the pump pressure stroke and the opening of the valve 51 will be'advanced to a time during the pumppressure stroke. The timl ing of the valve maybe said to lead the pump when the valve 51 opens and closes at the ends 4of the piston strokes. The.- capacity of the pump may be varied by changing the timing of the valve for pumping minute quantities of the Iiuid.

The outer end of -thebores carrying the tappets 61 are enlarged as shown at 13 to form a recess forreceiving the oil that is splashed on another fluid through the pipes 11. fluids .may be simultaneously pumped asdisthe tappets within the crank case and carried therealong. This recess is connected by the passageways 14 to the bores in which the crosshead body portions 31 are reciprocated. The passageways 14 are arranged'to be uncovered by the portions 31 as they near the end of the inward stroke. The passageways 31a in the crossheads are restricted and a sub-atmospheric pressure 'is developed in the lubricant pump chamber during the retracting period of the pumping stroke. When the crosshead uncovers the port of the passageway 14 all the oil collected in the recess 13 around the tappets 61 is drawn through the passage 14 into the lubricant pumping chamber. This avoids any loss of oil from around the tappets and dispenses` with the necessity of packing them.

The pump head 4I is provided with the intake passageway15 which extends transversely thereof and connects the valve ports back of the valve seat members 6|. 'Ihis passageway may be connected to the system. at either side of the pump as indicated by the pipe lines 16 and 11 in Fig. 3 or one side may be closed as indicated by the plug in dotted lines at v1B. If all three pistons are employed to pump the same uid the passageway 15 remains uninterrupted for its full shown in Fig. 3 the left hand pump may be supplied with one fluid through they connecting pipe 16 while the other pumps may be supplied with Thus two closed for instance in Letters Patent No. 1,855,866, issued April 26, 1932, and 4Letters Patent No. 1,925,643,4ssued September 5, 1933, and in my application for Letters Patent Serial No. 36,290, led August 15, 1935. l

The exhaust valves of this pump may be constructed in any suitable manner, such for instance as the intake valves. However, for-ordinary use the ball check type of valve when properly installed will perform satisfactorily. Thus 80 represents the outlet check valve balls arranged to be seated inwardly on the valve seating .members 8| in the valve chambers 82, 83 and' 84'positioned above the pump chambers 44, 45 and 46. Where such a. position is inconvenient the ball valve may be provided with' springs to normally maintain them on their seats.

These valve balls are preferably made from a hard alloy so as .to resist wear and corrosion.

The outlet valve chambers are closed by the plugs or bonnets 85. Thesev bonnetsare also employed for settingthe outlet valves and adjusting the lift thereof for high speed operation. This is accomplished by forcing the bonnet shoulder tight against the shoulder of the pump nead. This force permits theinner' end of the bonnet 85 to contact thelball valve 80, forcing it against its seat. The ball valves 80 being made of hardalloy will `not be injured by this pressure.v However the valve seat andthe inner end of the bonnet 85 will b'e indented, as shown at 86, being of softermaterial where they have beenv i contacted. by the ball. The indenture in the end of the bonnet and the valve seat created by cold kflowing of the metal by this compressive force cold works the surface thereof, making it hard and less susceptible to wear. A shim washer or washers 8l having a thickness corresponding to the desired lift of the ball valve is then placed between the bonnet and the pump head shoulders. By the removal of one of several shims that may be positioned under the bonnet I am enabled to compensate for any Wear that may occur on the valve structure and the inner end of the bonnet.

This method of seating and adjusting these ball check valves has been found to be. accurate and successful in determining their lift. The cold working of the metal of the seat and the inner end of the bonnets prolong the life of the valve.v Obviously the method of setting a valve is not limited to ball Valves.

88 represents the outlet passageway connecting the valve chambers 82, 83 and 84I for receiving the discharge from the three pump chambers. This passageway is connected to the outlet pipes 89 and 90 leading from opposite sides of the pump head. If only one outlet pipe is necessary for connecting theA pump to the system, one of the lead pipes may be Areplaced by the plug 9|, as shown in dotted lines in Fig. 3.

A pump head of this type may beemployed to pump iluids from different sources and subsequently mix them in the discharge passageway 88.

Referring now to Figs. 5, 6 and 'lV wherein I have shown a modification of the pump head 4I, 92 represents the inletand 93 the outlet passageways vfor the pump chambers 45 and 46. 94 represents the inlet and the outlet passageways for the pump chamber 44. Thus theA triplex pump has been converted to a duplex pump and a single pump in the same structure.

This displacement pump is provided `with a lixed stroke and when operating at a constant speed any change in the timing or setting of the inlet valve will change the quantity of the liquid displaced by the piston as described above. Thus the inlet valv'e setting controls the output of the pump at a constant speed. When the output of the pump is connected to a closed system, which may be represented by the valve 96 in the discharge line ,91, a pressure will be set up in the system by the constant displacement of the pump operated at a constant speed. This displacement pressure depends upon the opening of the valve 96 which controls the quantity of uid passing from the pump. To limit the pressure developed in the system I provide a by-.pass passageway 98 which in this instance connects the pump chamber -44 with the inlet passageway 94. The bypass or escape orice may bedirected to the atmosphere or" any other suitable place.

The passageway 98,'is: constructed to have a predetermined aperture.V The size of the aperture may be made iixed within the pump head casing as shown, or it-may be regulated by means of a valve. However, at aconstant 'pump speed the size of the aperture in Icombination with the displacement of the pump piston controls the amount of fluid that passes therethrough during the pressure stroke. If the valve 96 is closed the pressure developed in the pump chamber will be a maximum, as the total discharge of the pump due to the piston displacement must pass through the by-pass 98. Again if the valve 96 is opened to permit some of the fluid to pass therethrough then the pressure in the system will be lowered, as there are two channels throughwhich the iluid discharged from the pump may pass. Thus it is obvious that when pumping against a certain head, with a constant displacement capacity pump operated at a constant speed, the effective head pressure will decrease, since a part of the uid is by-passed.

Thus by controlling the quantity of the liquid forced through the by-pass during the compressio'n stroke at a constant operating speed I am enabled to regulate the limiting pressure that will be developed within the pumping chamber and the system.v By controlling the opening of the valve 96 the pressure in the system may be regulated within the limits created by the orifice and the other contributing factors.

By employing this by-pass on a displacement pump I may dispense with the ordinary .pressure relief valve arranged to maintain a predetermined pressure within a system and to exhaust the pressure therein when it exceeds a maximum.

` I am also enabled to dispense with the use of a regulator for maintaining a constant pressure within the system as the valve 96 measures the quantity of liquid leaving the system whichin turn controls the pressure developed therein owing to the predetermined size of the passageway 9B and the adjustable feature of the valve 96.

'I'here has long been a great need for a small pump to handle uids at a relatively high pressure and at the same time in small quantities. To ll the gap that exists between the mechanical lubricator type and the rotary centrifugal type I have developed the pump disclosed herein.

This pump has a wide application because of the low operating horse power required, the wide range of pressure, and the positive displacement feature resulting in high volumetric elliciency. Pure water, water containing various percentages of alkaline compounds, fuel oils, mineral oils and various chemicals are most readily handled by this pump. It is adaptable to a great variety of. uses such as boiler feed, boiler compound injection, condensate returns, small hydraulic presses, fuel oil pumps for oil burners, pumping of chemicals, air conditioning apparatus and control apparatus.

I claim: l

' 1.'In a displacement pump, the combination with the pump chamber, a piston working therein and a poppet Valve for the admission of uid to the chamber, ofa single crank for reciprocating the piston and operating the valve, and means whereby the speed of movement of the valve is increased as it seats and unseats.

2. In a displacement pump, the combination with the pump chamber, a piston working therein and a poppet valve tor the admission of fluid to the chamber, of a single eccentric means for reciprocating the piston and operating the valve, said means being arranged to increase the speed of movement of the valve in seating and unseating the same.

3. In a ldisplacement pump, the combination with the pump chamber, a piston working therein and a poppet valvefor the admission of uid to the chamber, of a single crank for reciprocating the piston and operating the valve, means whereby the speedof movement of the valve is increased as it seats and unseats, and means for adjusting the movement of the valve relative to that of the piston.

4. In a displacement pump, the combination with the pump chamber, a piston working therein and a poppet valve for the admissionfofipid to the chamber, of a single'eccentric means "for 75 'inlet valve to cause the the inlet valve to cause the reciprocating theV piston and operating the valve, said means nemg arranged to increase the speed `oli? movement of the valve in seating and unseating the same, and means for adjusting the lmovement of the valve relative to that of the piston.

5. In combination with a V pump chamber, a pump piston working therein, and inlet and outlet valvesv for th'e chamber, of a rotary crank con a plvoted bell crank one arm'of which is swung directly by the rst mentioned crank and the other arm of which is operatively connected to same to open and close in timed relation to the movement of the piston, and means for regulating the timing of..

the opening and closing oi the inlet valve.l

7. In combination with a pump chamber, a pump piston working therein, and inlet and outlet valves for the chamber, of a rotary crank connected to the piston to reciprocate the latter. a plvoted bell-crank lever one armo! which is swung directly by the rst mentioned crank, and operative connection between the other arm of the bell crank and the inlet valve-to cause the latter to open and' close in timed relation to the movement of the piston and comprising means for regulating the timing of the opening and closing of the inlet valve.

8. In combination with a pump chamber. a pump piston working in the chamber, and inlet and outlet valves for the chamber, cfa rotary Vsaid strap and the other for varying cause the same to open and close in timed relation to the movements of the piston.

9. Inl combination with a purr chamber, a pump piston working therein, and inlet and outlet valves for the chamber, of a rotary crank, a

strap encircling the crank and operatively connected to the piston to reciprocate the same, vand a pivoted bell crank one arm of which rides on said strap and the other arm of which is operatively connected to the inlet valve to cause the Same to open and close in timed relation .to the movements of the piston.

In combination with a pump chamber, a pump piston working therein, and inlet and outlet valves for the" chamber, of a rotary crank, a strap encircling the crank and operatively connected to the piston to reciprocate the same, a

plvoted bell crank one arm of which rides on arm of which is operainlet valve to open the tively connected to the to the movements of same in timed relation the piston, and means for regulating the timing of the opening and closing of the inlet valve.

11. In combination with a pump chamber, a pump piston working therein, and inlet and outlet valves for the chamber, of a rotary crank, a

strapl encircling the crank ar'l operatively connected to the piston to reciprocate the same, a plvoted bell crank one arm `of which rides on the strap. and operative connection between the other arm of the bell I for opening the latter in timed relation to the movements oi' the piston and comprising means forregulating the timing of the opening and closing of the inletvalve.k

12.. In a displacement pump, the combination with the pump chamber, a piston working therein and a poppet valve for the admission of iluid to the chamber, of a single crank for` reciprocating the piston -and to operate the valve, means whereby the speed oi' the movement of the valve is increased as it seats and unseats, and means the capacity of the pump independlpeed ofthe operation of the pump.

entlyof the YFRANK W. OFELDT.

crank and the inlet valve 

